Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segments
Number of operating segment	1
Cost of revenue
Costs and expenses with related parties	$ 0	$ 405
Sales and marketing
Costs and expenses with related parties	3,918	3,336
Adjustments Relating to Prior Period Disclosures of Related Party Cost of Revenue | Cost of revenue | Adjustment
Costs and expenses with related parties		(200)
Adjustments Relating to Prior Period Disclosures of Related Party Sales and Marketing expenses | Sales and marketing | Adjustment
Costs and expenses with related parties		$ 300